This is a new release which mainly fixes the installer, which named the executable in your program files folder "heidisql32.exe", not "heidisql.exe". Sounds minor, but I suppose there are quite a few links out there still pointing to heidisql.exe. The 10.1 installer now deletes that heidisql32.exe and installs the fresh heidisql.exe.
Thanks to forum user fyrye for reporting that issue.
Grab it from the download page. And don't forget to disable your adblocker :)